BananaNZ

I've grown bananas for a couple of years with no problems. I'm in New Zealand in zone 10b on friable clay. Heading into winter and funny things started happening- very thin pale leaves were emerging on some plants. A couple are also a bit tangled. We havn't had a frost yet.

Other points to note are that I've renovated my house and been chucking lots of old bit of plasterboard/drywall around the garden as a source of gypsum. I've also added bamboo mulch and fresh pinoak mulch. Maybe robbing nitrogen from the bananas?

Any ideas?

sirdoofus

Just curious - have you done a soil analysis to ascertain if your soil is high in sodium or low in calcium? I am wondering about the drywall, I don't know much about it but I would be concerned there may be compounds in the mix other than gypsum which might not be conducive to plant growth?

I think agricultural gypsum is primarily used to loosen hardpan, reduce sodium and add calcium...but is drywall the same thing? I think in a small garden, even in clay soil situations, there are better ways to loosen the soil. The addition of lots of mulch being the primary one as I understand it.

I don't think most mulches are going to rob nitrogen from the plant, but adding nitrogen is a cheap, easy fix if that happens to be what is going on.

There are some mulches that could, over time, be problematic, but I think they are by far the exception; most items the average gardener is likely to use are fine. Having said that, there are a couple of things I won't use abundantly, repeatedly over time and for me here, that includes cedar, oak products (I don't know if pinoak is a type of oak? There is a variety of oak called a Pin Oak - same thing?) and walnut products to name a few. Doesn't mean occasional use will be problematic though and even applied abundantly it would take time to manifest a problem.

I am a huge fan of mulch, lots of it, and I use pretty much whatever is easily and cheaply available. I think in most situations that I am familiar with, its very hard to go wrong with this philosophy, but then I have never grown anything in 10b.

Hopefully by now things have started to sort themselves out. Good luck and keep us posted.

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smeash

Your last photo to my eye looks like classic overfertilization. I push my plants hard and i get crazy twisty leaves like that, as well as leaf burn etc.

BananaNZ

Thanks for the feedback. I've not done a soil test but planning on it. At the moment definitely leaning towards over fertilisation. I think what's happened is rapid growth due to hight N and the some of the other nutrients can't keep up with the rapid growth.

I like mulching too but need to get some more. We've had a low level frost recently and a few bananas are a bit burnt. Will post an update closer to spring when things start growing again.

Yes I meant pin oak. What is problematic with using those mulches?

Thanks for your help

sirdoofus

I want to stress the problematic issues that may arise from the 3 products mentioned assume repeated application over time. Occasional or lite use is not likely to pose any challenges and the benefit to a good layer of mulch likely significantly outweighs any downsides. Also, thoroughly composting the material before application probably negates any harms that could arise from heavy use of fresh material

Cedar (Western Red Cedar and ralated species anyway, don't know about true cedars as they are not really an option for me so haven't studied them) can release acetic acid into the soil which may harm plants. It is a good pest repellent but may also discourage pollinators.

Oak also can acidify the soil and the tannins (I think) in some oak species (don't know about Pin Oak) are allelopathic and may adversely affect growth of sensitive plants

Walnut contains a compound called juglone which is toxic to some plants (I don't know if bananas are sensitive).

Having said that, If all that was available to me was, for example oak, I would still use it and just work it out. Fortunately for me I have many options so don't have to rely on any one thing. And again, this doesn't mean I won't use them, I do in fact use oak leaves from time to time as I do have a good source for them, just not abundantly or exclusively.

Hope that helps

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smeash

Of note here.. I have put over 200 cu. yards of mostly oak wood chips in my yard, with tons around my bananas up to a foot thick.. Zero adverse effects, in fact quite the opposite. The only remotely adverse effect is the presence of stinkhorn mushrooms in early spring.. they are harmless, other than the odor.. they love decaying hardwood. They are only an issue during the damp cool spring though, and they help break down the chips.
The soil that develops from broken down woodchips is pure gold. They break down fast here in Florida.. and I usually have several truckloads dropped off each month. I keep piling them on and they keep turning into gorgeous soil. Good weed supression, and a nice clean look for my natural areas of the yard.
As far as walnut chips.. I believe only black walnut is the problem, but not 100% sure.

sirdoofus

Your landscape looks awesome and its good to know the oak chips work well, thanks for sharing. Do you know what kind of oak?

I hear ****ake (that's kind of funny) mushrooms love growing on oak logs, have you ever tried inoculating a fresh load of oak chips? I don't know if it would work but it would be kind of cool if it did.

I believe you are correct with regard to black walnut being most problematic, and I think, even though the wood does contain juglone, the worst parts are the parts that fall off the tree...minus the nuts themselves I am assuming.

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Who keeps calling me nuts??

smeash

All of my chips are live oak or laurel oak.. both prevalent species down here. Ive used pine as well. Ive considered inoculating an area of chips, but so many wild mushroom species grow in the chips that i would be concerned about poisoning myself lol. I should also note that in regard to the chips affecting soil PH, that our soil here is basically sand, with a PH of 7-7.5 so pretty basic.. acidification would likely be helpful in my situation, but I havent tested the soil.

Akula

I don't think that's related to the gypsum.

Maybe too much water combined with cooler temps or maybe lots of cloudy weather? Looks kinda boggy in that front section. Raise the bed a bit? Suggest checking your ph level too. I certainly wouldn't fertilize once the temps start to drop.

Good luck!